Maurice tilhet



. UNITED- STATES PATE T OFFICE.

MAURICE TILEIET, OF PARIS, FRANCE.

PROCESS OF REPRODUCING DRAWINGS AND DESIGNS.

SPECIFICATION forming part of Letters Patent No. 251,746, dated January 3, 1882.

Application filed January 3, 1881. (No specimens.) Patented in France August 21, 1879, in England November 26, 1880, in Belgium November 27, 1880, and in Germany November 29, 1880. I

To all whom it may concern:

Be it known that I, MAURICE TILHET, of Paris, in the Republic of France, have invented a certain new and useful Improved Process of Reproducing Drawings and Designs; and I do hereby declare thattbe following isafull, clear, and exact description thereof.

This invention has for its object a novel method of reproducing copies of all kinds of drawings or other designs, and it is applicable to the reproduction of such copies upon any kind of paper, and either in black, red, blue, green, or any other color.

In order to put the invention in operation, the paper upon which the design is to boreproduced in order to prepare a. negative copy is first passed through a bath composed of the following materials, in about the proportions given-that is to say: white soap, thirty parts, by weight; alum, thirty parts, by weight; Flanders glue, forty parts, by weight; the whites of eggs beaten up, ten parts, by weight; glacial acetic acid, two parts, by weight; alco hot at ten parts, by weight; water, five hundred parts, by weight. The paper, after leaving this bath, is then passed through a second bath, composed as follows: burnt umber ground in alcohol, fifty parts, by Wright; black pigment, twenty parts, by weight; Flanders glue, ten parts, by weight; water, five hundred parts, by weight; bichromate of pot ash, ten parts, by weight. The paper having been thus treated must be keptin a dark place.

In order to prepare positive-paper for the prints, :1 bath is used similar to the last, but without the umber, for which blaclrpigment is substituted; or to obtain colored proofs instead of black ones the black pigment isle placed by a pigment of rrd, blue, or any other desired color.

To prepare the copies, the design or drawing is placed in an ordinary photographicprinting frame, the back of the design being next to the glass, and a sheet of negative paper, prepared in the way first described, is placed in contact with it. The frame is then exposed to light, two minutes exposure being sufficient in good weather. The sensitive paper is then removed from the frame in a dark place and is placed in water, becomes visible in white, allowed to dry.

In order to obtain positive pictures from the negative thus prepared, the latter is placed in the printing-frame with a sheet of the positive paper in contact with it, and after exposure to light for a sufficient timethat is to say, about two minutesthe positive paper is removed in a dark place and is plunged into water, which removes the part of the pigment which has not been effected by the light without its being necessary to touch it.

Any number of copies of the design or drawing may be produced by the novel method described upon any kind of paper and in any color or colors.

The proportion of the different materials used to prepare the baths as above described may be varied to suit varying circumstances.

Having fully described my invention, what I desire to claim, and secure by Letters Patent, 1s-- l.

1. In the process of preparing negative paper for reproducing drawings and designs, the two baths consisting, first, of white soap, alum, Flanders glue, whites of eggs beaten up, glacial acetic acid, alcohol, and water, and, seewhen the design and the paper then 0nd, of burnt umber ground in alcohol, black,

pigment, Flanders glue, bichromate of potash, and water, all in about the relative proportions described.

2. In the process of preparing positive paper for reproducing drawings and designs from negatives upon paper prepared in the manner described and claimed, a bath consisting of black or colored pigments, Flanders glue, bi-

chromate of potash, and Water, all in about the relative proportions described.

In testimony whereof I, M. TILHET, have signed this specification in the presence of two subscribing witnesses.

M. TILH ET.

Witnesses:

E. DIENAID, R0131. M. HOOPER. 

